Very sorry for your loss, Gillstone. I was widowed at 31 with 3 children. It's hard.
The GoFundMe sounds well intended but completely unnecessary. Can you roll your wife's 401 into your own Vanguard account? Those fees, ugh. There should be no penalty or tax on spousal transfers.
You didn't ask for specific advice on the survivors' benefits, but here is what I've learned. Each year the SSA will send you a Representative Payee Report. At the center of this are the questions "were all monies spent for the care of the beneficiary? Was any money saved?" If "yes" on savings, the SSA will become interested in that account. By their guideline, the saved funds must be turned over to the beneficiary at 18 (or 19 if still in high school) Saving money for college is of course a smart thing, but it's best if it comes from 'your' money. I use the SSA to pay for all kid related expenses like sports, clothing, trips and camp as well as a big percentage of mortgage, utility, food and car expenses. College savings comes from my own funds and in that way I can control what happens to the money. If for example, your 18 year old elects not to go to college and instead wants to buy a van and follow a band around the country, they will have to find another way to finance it rather than the $30,000 that was just dropped into their lap from "their" saved SSA benefits.
You may also lose your child tax deduction unless you spend a lot on private schools or tutoring for your children.
Again, my condolences and please go easy on yourself during this time.